Processing of cobaltous sulpha/dithionate liquors derived from cobalt resource

ABSTRACT

A process for water removal and/or recycling of sodium sulfate and/or sodium dithionate containing liquors derived from processing cobalt resource material essentially free of lithium comprising the steps of precipitation of cobalt as cobaltous carbonate or cobaltous hydroxide followed by removal thereof from the liquor, crystallization of sodium sulfate and sodium dithionate and removal of the crystals, followed by heating of the crystals to anhydrous sodium sulfate, sulphur dioxide and water and then separating the anhydrous sodium sulfate.

PREVIOUS APPLICATION

This application is a non-provisional application claiming the priorityof provisional application No. 62/421,139, filed on Nov. 11, 2016.

TECHNICAL FIELD

The present invention relates to the recovery of water and sulphatesalts from sulphate and dithionate containing liquors such as thosederived from hydrometallurgical processing of cobalt containing resourcematerial such as cathode materials from lithium ion batteries.

BACKGROUND OF THE INVENTION

It is generally known that cobalt may be leached from higher valentcobalt containing resource material, such as cobalt (III) oxide, using areducing agent such as sulphur dioxide in combination with sulphuricacid, to produce cobaltous sulphate and cobaltous dithionate. This isdescribed in the following reactions:

Co₂O₃+SO₂+H₂SO₄=2CoSO₄+H₂O

Co₂O₃+2SO₂+H₂SO₄=2CoS₂O₆+H₂O

Cobalt present in rechargeable lithium ion battery cathode material isin the trivalent state and is expected to be leached with sulphurdioxide and sulphuric acid. Lithium cobalt oxide, such as LiCoO₂ is acommon cathode material for high energy lithium ion batteries typicallyused in personal electronic devices is expected to leach according tothe following reactions:

2LiCoO₂+SO₂+2H₂SO₄═Li₂SO₄+2CoSO₄+2H₂O

2LiCoO₂+3SO₂+2H₂SO₄═Li₂SO₄+2CoS₂O₆+2H₂O

2LiCoO₂+4SO₂+2H₂SO₄═Li₂S₂O₆+2CoS₂O₆+2H₂O

Experimental work conducted on leaching lithium cobalt oxide withsulphur dioxide and sulphuric acid confirmed that up to 100% extractionsof lithium and cobalt were achieved and that dithionate was detected inall leach tests conducted.

Lithium nickel manganese cobalt oxide, such asLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ is an emerging cathode material havingboth high energy and high power suitable for use in electric vehicles isexpected to leach according to the following reactions:

2LiNi_(0.33)Mn_(0.33)Co_(0.33)O₂+SO₂+2H₂SO₄═Li₂SO₄+2(Ni,Co,Mn)SO₄+2H₂O

2LiNi_(0.33)Mn_(0.33)Co_(0.33)O₂+3SO₂+2H₂SO₄═Li₂SO₄+2(Ni,Co,Mn)CoS₂O₆+2H₂O

2LiNi_(0.33)Mn_(0.33)Co_(0.33)O₂+4SO₂+2H₂SO₄═Li₂S₂O₆+2(Ni,Co,Mn)S₂O₆+2H₂O

(Ni,Co,Mn)SO₄ and (Ni,Co,Mn)S₂O₆ represent a mixed metal sulphate and amixed metal dithionate respectively.

Experimental work conducted on leaching lithium nickel manganese cobaltoxide with sulphur dioxide and sulphuric acid confirmed that up to 100%extractions of lithium, nickel, manganese and cobalt were achieved andthat dithionate was detected in all leach tests conducted.

Lithium nickel cobalt aluminum oxide, such asLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ is another emerging cathode materialhaving both high energy and high power suitable for use in electricvehicles is expected to leach according to the following reactions:

2LiNi_(0.8)Co_(0.15)Al_(0.05)O₂+SO₂+2H₂SO₄═Li₂SO₄+2(Ni,Co,Al)SO₄+2H₂O

2LiNi_(0.8)Co_(0.15)Al_(0.05)O₂+3SO₂+2H₂SO₄═Li₂SO₄+2(Ni,Co,Al)CoS₂O₆+2H₂O

2LiNi_(0.8)Co_(0.15)Al_(0.05)O₂+4SO₂+2H₂SO₄═Li₂S₂O₆+2(Ni,Co,Al)S₂O₆+2H₂O

(Ni,Co,Al)SO₄ and (Ni,Co,Al)S₂O₆ represent a mixed metal sulphate and amixed metal dithionate respectively.

Experimental work conducted on leaching lithium nickel manganese cobaltoxide with sulphur dioxide and sulphuric acid confirmed that up to 100%extractions of lithium, nickel, cobalt and aluminum were achieved andthat dithionate was detected in all leach tests conducted.

There is no known prior art method of recovering valuable metals fromspent lithium ion battery cathode materials containing cobalt that usesreductive leaching with sulphur dioxide while dealing with dithionatesand recovery of water in an energy efficient manner. Although U.S. Pat.No. 8,460,631 describes the processing of manganese sulphate andmanganese dithionate containing liquors, which also contain sodiumsulphate and sodium dithionate, it is not obvious from that inventionhow sodium sulphate and sodium dithionate could be processed togetherwith cobaltous sulphate and cobaltous dithionate in the presence orabsence of lithium sulphate and lithium dithionate. Furthermore, it hasbeen discovered that the process of dealing with dithionates andrecovery of water and recirculating treated solutions back to the leachin a locked cycle manner significantly improves the recovery of lithiumwhen present.

SUMMARY OF THE INVENTION

Accordingly one embodiment of the invention is a process of waterremoval and/or recycling from sodium sulphate and/or sodium dithionatecontaining liquors derived from processing cobalt resource materialessentially free of lithium, comprising the steps of: a. precipitationof cobalt as cobaltous carbonate in whole or in part followed by itsremoval in whole or in part from the liquor for example bycentrifugation or filtration; b. crystallization of sodium sulphate andsodium dithionate to separate the majority of sodium sulphate and sodiumdithionate from solution; removal of sodium sulphate and sodiumdithionate crystals; c. heating of sodium sulphate and sodium dithionatecrystals to form anhydrous sodium sulphate, sulphur dioxide and water(steam); and d. separation of anhydrous sodium sulphate.

Another embodiment of the invention is a process of water removal and/orrecycling from sodium sulphate and/or sodium dithionate containingliquors derived from processing cobalt resource material containinglithium, comprising the steps of; a. precipitation of cobalt ascobaltous carbonate in whole or in part and lithium in whole or in partas lithium carbonate followed by their removal in whole or in part fromthe liquor for example by centrifugation or filtration; b.crystallization of sodium sulphate and sodium dithionate to separate themajority of sodium sulphate and sodium dithionate from solution; c.removal of sodium sulphate and sodium dithionate crystals; and e.separation of anhydrous sodium sulphate.

A further embodiment of the invention is a process of water removaland/or recycling from sodium sulphate and/or sodium dithionatecontaining liquors derived from processing cobalt resource materialessentially free of lithium, comprising the steps of: a. precipitationof cobalt as cobaltous hydroxide in whole or in part followed itsremoval in whole or in part from the liquor for example bycentrifugation or filtration; b. crystallization of sodium sulphate andsodium dithionate to separate the majority of sodium sulphate and sodiumdithionate from solution; c. removal of sodium sulphate and sodiumdithionate crystals; d. heating of sodium sulphate and sodium dithionatecrystals to form anhydrous sodium sulphate, sulphur dioxide and water(steam); and e. separation of anhydrous sodium sulphate.

A still further embodiment of the invention is a process of waterremoval and/or recycling from sodium sulphate and/or sodium dithionatecontaining liquors derived from processing cobalt resource materialcontaining lithium, comprising the steps of: a. precipitation of cobaltas cobaltous hydroxide in whole or in part followed by its removal inwhole or in part from the liquor for example by centrifugation orfiltration; b. precipitation of lithium as lithium carbonate in whole orin part from the cobaltous hydroxide stripped liquor of 4a, followed byits removal in whole or in part from the liquor for example bycentrifugation; c. crystallization of sodium sulphate and sodiumdithionate to separate the majority of sodium sulphate and sodiumdithionate from solution; d. removal of sodium sulphate and sodiumdithionate crystals; and e. separation of anhydrous sodium sulphate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 3 illustrates process flowsheets for a first embodiment ofthe present invention, with “S” indicating solid phase and “L”indicating liquid phase.

FIG. 1 illustrates a process flowsheet for a first embodiment to treatspent lithium cobalt oxide.

FIG. 2 illustrates a process flowsheet for a first embodiment to treatspent lithium nickel manganese cobalt oxide.

FIG. 3 illustrates a process flowsheet for a first embodiment to treatspent lithium nickel cobalt aluminum oxide.

FIG. 4 illustrates a process flowsheet for a second embodiment to treatspent lithium cobalt oxide.

FIG. 5 illustrates a process flowsheet for a second embodiment to treatspent lithium nickel manganese cobalt oxide.

FIG. 6 illustrates a process flowsheet for a second embodiment to treatspent lithium nickel cobalt aluminum oxide.

FIG. 7 illustrates a process flowsheet for a third embodiment to treatspent lithium cobalt oxide.

FIG. 8 illustrates a process flowsheet for a third embodiment to treatspent lithium nickel manganese cobalt oxide.

FIG. 9 illustrates a process flowsheet for a third embodiment to treatspent lithium nickel cobalt aluminum oxide.

BEST MODE FOR CARRYING OUT THE INVENTION

In accordance with the present invention there is provided a process forthe hydrometallurgical processing of cobaltous sulphate and cobaltousdithionate containing liquors derived from sulphurous acid and sulphuricacid leaching of cobalt (III) oxide containing resource material such asthose recovered from the cathode materials of lithium ion batteries.

For embodiment one, referring to FIGS. 1-3.

Cobaltous sulphate and cobaltous dithionate containing liquor aretreated with sodium carbonate to form cobaltous carbonate solids and asodium sulphate and sodium dithionate containing liquor.

Lithium sulphate and lithium dithionate, if present, will be partiallyprecipitated as lithium carbonate solids along with the cobaltouscarbonate solids.

Cobaltous carbonate containing solids and lithium carbonate solids, ifpresent, are removed from the carbonate treated liquor by filtration orcentrifugation.

Cobaltous carbonate containing solids and lithium carbonate solids, ifpresent, are washed to remove soluble impurities and produce cleanmaterials for reuse, such as for cathode materials for lithium ionbatteries.

Sodium sulphate and sodium dithionate along with remaining lithiumsulphate and lithium dithionate, if present, containing filtrate orcentrifugate are treated with a crystallizer to crystallize the majorityof sodium sulphate and sodium dithionate crystals.

Crystallization can be conducted by cooling to precipitate (crystallize)sodium sulphate decahydrate and sodium dithionate dihydrate or bymulti-effect crystallization to precipitate (crystallize) anhydroussodium sulphate and sodium dithionate.

Sodium sulphate and sodium dithionate crystals are heated to atemperature sufficient to convert sodium dithionate crystals to sodiumsulphate and recyclable sulphur dioxide and water for leaching of cobaltresource material. The temperatures for converting sodium dithionate tosodium sulphate and sulphur dioxide are described by Chow et al, (“NewDevelopments in the Recovery of Manganese from Lower-grade Resources”,Minerals & Metallurgical Processing, Vol. 29, No. 1, February 2012, pp70-71).

The crystallizer liquor, having the majority of sodium sulphate andsodium dithionate removed and containing lithium sulphate and lithiumdithionate, if lithium was present in the resource material, is recycledinto the leach circuit for further recovery of lithium and cobalt thatwas not recovered previously and reuse of water in an energy efficientmanner.

Alternatively, a portion of the crystallizer liquor, having the majorityof sodium sulphate and sodium dithionate removed and containing lithiumsulphate and lithium dithionate, if lithium was present in the resourcematerial, can be passed through a nanofiltration membrane to create awater rich sulphate and dithionate free liquor output for recycling anda sodium sulphate and sodium dithionate concentrate along with lithiumsulphate and lithium dithionate for recycling to the sodium sulphate andsodium dithionate crystallizer.

The precipitated cobalt and lithium containing compounds can be used tomanufacture cathode materials for lithium ion batteries. This isgenerally conducted by combining the desired ratio of cobalt and lithiumcontaining compounds and performing a heat treatment procedure on themixture. Jones et al (“Li_(x)CoO₂ (0<x≤1): A New Cathode Material forBatteries of High Energy Density”, Solid State Ionics, ¾, 1981, pp171-174) describes a method to manufacture lithium cobalt oxide cathodematerials by treating lithium and cobalt compounds. Lu et al (“U.S. Pat.No. 8,685,565”, April 2014) describes a method to manufacture lithiumnickel manganese cobalt oxide by treating lithium, nickel, manganese andcobalt compounds. Kim et al (“Synthesis of High-Density Nickel CobaltAluminum Hydroxide by Continuous Coprecipitation Method”, ACS AppliedMaterials & Interfaces, 4, 2012, pp 586-589) describes a method tomanufacture lithium nickel cobalt aluminum oxide by treating lithium,nickel, cobalt and aluminum compounds. Commercial battery manufacturerstypically develop and use their own proprietary treatment methods toproduce cathode materials for lithium ion batteries.

The conversion of cobaltous sulphate and cobaltous dithionate to sodiumsulphate and sodium dithionate provides for novel methods of dealingwith dithionates, increasing the recovery of lithium and recycling waterin an energy efficient manner.

For embodiment two, referring to FIGS. 4-6

Cobaltous sulphate and cobaltous dithionate containing liquors aretreated with sodium hydroxide to form cobaltous hydroxide solids and asodium sulphate and sodium dithionate containing liquor;

Cobaltous hydroxide containing solids are removed from the hydroxidetreated liquor by filtration or centrifugation;

Cobaltous hydroxide containing solids are washed to remove solubleimpurities and produce clean materials for reuse, such as for cathodematerials for lithium ion batteries;

The addition of sodium carbonate to the remaining solution precipitatespart of the lithium, if present, as lithium carbonate;

Lithium carbonate solids are removed from the carbonate treated liquorby filtration or centrifugation;

Lithium carbonate solids are washed to remove soluble impurities andproduce clean materials for reuse, such as for cathode materials forlithium ion batteries;

Sodium sulphate and sodium dithionate along with remaining lithiumsulphate and lithium dithionate, if present, containing filtrate orcentrifugate are treated with a crystallizer to crystallize the majorityof sodium sulphate and sodium dithionate crystals;

Crystallization can be conducted by cooling to precipitate (crystallize)sodium sulphate decahydrate and sodium dithionate dihydrate or bymulti-effect crystallization to precipitate (crystallize) anhydroussodium sulphate and sodium dithionate;

Sodium sulphate and sodium dithionate crystals are heated to atemperature sufficient to convert sodium dithionate crystals to sodiumsulphate and recyclable sulphur dioxide and water for leaching of cobaltresource material;

The crystallizer liquor, having the majority of sodium sulphate andsodium dithionate removed and containing lithium sulphate and lithiumdithionate, if lithium was present in the resource material, is recycledinto the leach circuit for further recovery of lithium and cobalt thatwas not recovered previously and reuse of water in an energy efficientmanner.

Alternatively, a portion of the crystallizer liquor, having the majorityof sodium sulphate and sodium dithionate removed and containing lithiumsulphate and lithium dithionate, if lithium was present in the resourcematerial, can be passed through a nanofiltration membrane to create awater rich sulphate and dithionate free liquor output for recycling anda sodium sulphate and sodium dithionate concentrate along with lithiumsulphate and lithium dithionate, if lithium was present in the resourcematerial, for recycling to the sodium sulphate and sodium dithionatecrystallizer.

For embodiment three, referring to FIGS. 7-9.

Cobaltous sulphate and cobaltous dithionate containing liquors aretreated with lithium hydroxide to form cobaltous hydroxide solids and alithium sulphate and lithium dithionate containing liquor;

The lithium hydroxide can be produced by treating lithium carbonaterecovered by previous operation of the flowsheet. Wietelmann et al(“Lithium and Lithium Compounds”, Ullmann's Encyclopedia of IndustrialChemistry, Wiley-VCH Verlag GmbH & Co, 2013, pp 24) describes a methodof producing lithium hydroxide by reacting lithium carbonate withcalcium hydroxide;

Cobaltous hydroxide containing solids are removed from the hydroxidetreated liquor by filtration or centrifugation;

Cobaltous hydroxide containing solids are washed to remove solubleimpurities and produce clean materials for reuse, such as for cathodematerials for lithium ion batteries;

The addition of sodium carbonate to the remaining solution precipitatespart of the lithium, if present, as lithium carbonate;

Lithium carbonate solids are removed from the carbonate treated liquorby filtration or centrifugation;

Lithium carbonate solids are washed to remove soluble impurities andproduce clean materials for reuse, such as for cathode materials forlithium ion batteries;

Sodium sulphate and sodium dithionate along with remaining lithiumsulphate and lithium dithionate, if present, containing filtrate orcentrifugate are treated with a crystallizer to crystallize the majorityof sodium sulphate and sodium dithionate crystals;

Crystallization can be conducted by cooling to precipitate (crystallize)sodium sulphate decahydrate and sodium dithionate dihydrate or bymulti-effect crystallization to precipitate (crystallize) anhydroussodium sulphate and sodium dithionate;

Sodium sulphate and sodium dithionate crystals are heated to atemperature sufficient to convert sodium dithionate crystals to sodiumsulphate and recyclable sulphur dioxide and water for leaching of cobaltresource material;

The crystallizer liquor, having the majority of sodium sulphate andsodium dithionate removed and containing lithium sulphate and lithiumdithionate, if lithium was present in the resource material, is recycledinto the leach circuit for further recovery of lithium and cobalt notrecovered previously and reuse of water in an energy efficient manner.

Alternatively, a portion of the crystallizer liquor, having the majorityof sodium sulphate and sodium dithionate removed and containing lithiumsulphate and lithium dithionate can be passed through a nanofiltrationmembrane to create a water rich sulphate and dithionate free liquoroutput for recycling and a sodium sulphate and sodium dithionateconcentrate along with lithium sulphate and lithium dithionate forrecycling to the sodium sulphate and sodium dithionate crystallizer.

The precipitated cobalt and lithium containing compounds can be used tomanufacture cathode materials for lithium ion batteries.

With respect to embodiment one for treatment of lithium cobalt oxideshown in FIG. 1, the flowsheet is described as follows:

In the leach reactor (12), spent lithium ion battery cathode materialwith the chemical formula LiCoO₂ is combined and mixed with SO₂ andH₂SO₄ reagent and a solution containing water, and possibly lithiumand/or cobalt that has not been recovered previously from the laststages of the flowsheet. Lithium and cobalt are dissolved in solutionproducing a leach solution containing cobalt sulphate, cobaltdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (20) wheresodium carbonate solution is added and mixed to precipitate cobalt andpart of the dissolved lithium as cobalt and lithium carbonate solid andforming a solution containing mainly lithium sulphate, lithiumdithionate, sodium sulphate and sodium dithionate.

The precipitation reactions occur as follows:

CoSO₄+Na₂CO₃═CoCO₃+Na₂SO₄ Near Complete Conversion

CoS₂O₆+Na₂CO₃═CoCO₃+Na₂S₂O₆ Near Complete Conversion

Li₂SO₄+Na₂CO₃═Li₂CO₃+Na₂SO₄ Partial Conversion

Li₂S₂O₆+Na₂CO₃═Li₂CO₃+Na₂S₂O₆ Partial Conversion

The slurry containing a mixture of solids and liquids is filtered (14)to separate lithium carbonate and cobalt carbonate which is rinsed toproduce a collected product (16).

The filtrate is transferred to a crystallizer (18) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (22). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (24)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (26) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (28) to produce clean water (30) for rinsingproducts and reuse of the spent rinse water (32) back to the leach. Theconcentrate from nanofiltration (34) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The mixed lithiumcarbonate and cobalt carbonate collected product (16) is heat treated(36) to manufacture new cathode compounds for use in lithium ionbatteries. If required, additional lithium carbonate and or cobaltcarbonate may be added to the collected product to achieve the desiredratio of lithium and cobalt prior to heat treatment.

With respect to embodiment one for treatment of lithium nickel manganesecobalt oxide shown in FIG. 2, the flowsheet is described as follows:

In the leach reactor (40), spent lithium nickel manganese cobalt oxidecathode materials for example with the chemical formulaLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or manganese and/or cobalt that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,manganese and cobalt are dissolved in solution producing a leachsolution containing a nickel manganese cobalt sulphate, nickel manganesecobalt dithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (48) wheresodium carbonate is added and mixed to precipitate nickel, manganese andcobalt and part of the dissolved lithium as nickel, manganese, cobaltand lithium carbonate solid and forming a solution containing mainlylithium sulphate, lithium dithionate, sodium sulphate and sodiumdithionate.

The precipitation reactions occur as follows:

(Ni,Mn,Co)SO₄+Na₂CO₃═(Ni,Mn,Co)CO₃+Na₂SO₄ Near Complete Conversion

(Ni,Mn,Co)S₂O₆+Na₂CO₃═(Ni,Mn,Co)CO₃+Na₂S₂O₆ Near Complete Conversion

Li₂SO₄+Na₂CO₃═Li₂CO₃+Na₂SO₄ Partial Conversion

Li₂S₂O₆+Na₂CO₃═Li₂CO₃+Na₂S₂O₆ Partial Conversion

The slurry containing a mixture of solids and liquids is filtered (42)to separate lithium carbonate and nickel manganese cobalt carbonatewhich is rinsed to produce a collected product (44).

The filtrate is transferred to a crystallizer (46) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (50). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (52)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (54) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (56) to produce clean water (58) for rinsingproducts and reuse of the spent rinse water (60) back to the leach. Theconcentrate from nanofiltration (62) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The mixed lithiumcarbonate and nickel manganese cobalt carbonate collected product (44)is heat treated (64) to manufacture new cathode compounds for use inlithium ion batteries. If required, additional lithium, nickel,manganese and or cobalt compounds may be added to the collected productto achieve the desired ratio of lithium, nickel, manganese and cobaltprior to heat treatment.

With respect to embodiment one for treatment of lithium nickel cobaltaluminum oxide shown in FIG. 3, the flowsheet is described as follows:

In the leach reactor (70), spent lithium nickel cobalt aluminum oxidecathode materials for example with the chemical formulaLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or cobalt and/or aluminum that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,cobalt and aluminum are dissolved in solution producing a leach solutioncontaining a nickel cobalt aluminum sulphate, nickel cobalt aluminumdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (78) wheresodium carbonate is added and mixed to precipitate nickel, cobalt andaluminum and part of the dissolved lithium as nickel, cobalt, aluminumand lithium carbonate solid and forming a solution containing mainlylithium sulphate, lithium dithionate, sodium sulphate and sodiumdithionate.

The precipitation reactions occur as follows:

(Ni,Co,Al)SO₄+Na₂CO₃═(Ni,Co,Al)CO₃+Na₂SO₄ Near Complete Conversion

(Ni,Co,Al)S₂O₆+Na₂CO₃═(Ni,Co,Al)CO₃+Na₂S₂O₆ Near Complete Conversion

Li₂SO₄+Na₂CO₃═Li₂CO₃+Na₂SO₄ Partial Conversion

Li₂S₂O₆+Na₂CO₃═Li₂CO₃+Na₂S₂O₆ Partial Conversion

The slurry containing a mixture of solids and liquids is filtered (72)to separate lithium carbonate and nickel cobalt aluminum carbonate whichis rinsed to produce a collected product (74).

The filtrate is transferred to a crystallizer (76) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (80). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (82)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (84) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (86) to produce clean water (88) for rinsingproducts and reuse of the spent rinse water (90) back to the leach. Theconcentrate from nanofiltration (92) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The mixed lithiumcarbonate and nickel cobalt aluminum carbonate collected product (74) isheat treated (94) to manufacture new cathode compounds for use inlithium ion batteries. If required, additional lithium, nickel, cobaltand or aluminum compounds may be added to the collected product toachieve the desired ratio of lithium, nickel, cobalt and aluminum priorto heat treatment.

With respect to embodiment two for treatment of lithium cobalt oxideshown in FIG. 4, the flowsheet is described as follows:

In the leach reactor (100), spent lithium ion battery cathode materialswith the chemical formula LiCoO₂ is combined and mixed with SO₂ andH₂SO₄ reagent and a solution containing water, and possibly lithiumand/or cobalt that has not been recovered previously from the laststages of the flowsheet. Lithium and cobalt are dissolved in solutionproducing a leach solution containing cobalt sulphate, cobaltdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (108) wheresodium hydroxide is added and mixed to selectively precipitate cobalt ascobalt hydroxide and forming a solution containing mainly lithiumsulphate, lithium dithionate, sodium sulphate and sodium dithionate.

The precipitation reactions occur as follows:

CoSO₄+2NaOH═Co(OH)₂+Na₂SO₄ Near Complete Conversion

CoS₂O₆+2NaOH═Co(OH)₂+Na₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (102)to separate the cobalt hydroxide which is rinsed to produce a collectedproduct (104).

The filtered solution is transferred to a second precipitation reactor(106) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (118)to separate lithium carbonate which is rinsed to produce a collectedproduct (120).

The filtrate is transferred to a crystallizer (114) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (116). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (110)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (112) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (122) to produce clean water (124) for rinsingproducts and reuse of the spent rinse water (126, 128) back to theleach. The concentrate from nanofiltration (130) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The lithium carbonate(120) and cobalt hydroxide (104) collected products are mixed to thedesired ratio of lithium and cobalt and heat treated (132) tomanufacture new cathode compounds for use in lithium ion batteries. Ifrequired, additional lithium and or cobalt compounds may be added to thecollected product to achieve the desired ratio of lithium and cobaltprior to heat treatment.

With respect to embodiment two for treatment of lithium nickel manganesecobalt oxide shown in FIG. 5, the flowsheet is described as follows:

In the leach reactor (140), spent lithium nickel manganese cobalt oxidecathode materials for example with the chemical formulaLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or manganese and/or cobalt that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,manganese and cobalt are dissolved in solution producing a leachsolution containing nickel manganese cobalt sulphate, nickel manganesecobalt dithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (148) wheresodium hydroxide is added and mixed to selectively precipitate nickel,manganese and cobalt as nickel manganese cobalt hydroxide and forming asolution containing mainly lithium sulphate, lithium dithionate, sodiumsulphate and sodium dithionate.

The precipitation reactions occur as follows:

(Ni,Mn,Co)SO₄+2NaOH═(Ni,Mn,Co)(OH)₂+Na₂SO₄ Near Complete Conversion

(Ni,Mn,Co)S₂O₆+2NaOH═(Ni,Mn,Co)(OH)₂+Na₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (142)to separate the nickel manganese cobalt hydroxide which is rinsed toproduce a collected product (144).

The filtered solution is transferred to a second precipitation reactor(146) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (158)to separate the lithium carbonate which is rinsed to produce a collectedproduct (160).

The filtrate is transferred to a crystallizer (154) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (156). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (150)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (152) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (162) to produce clean water (164) for rinsingproducts and reuse of the spent rinse water (166, 168) back to theleach. The concentrate from nanofiltration (170) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The lithium carbonate(160) and nickel manganese cobalt hydroxide (144) collected products aremixed to the desired ratio of lithium, nickel, manganese and cobalt andheat treated (172) to manufacture new cathode compounds for use inlithium ion batteries. If required, additional lithium, nickel,manganese and or cobalt compounds may be added to the collected productto achieve the desired ratio of lithium, nickel, manganese and cobaltprior to heat treatment.

With respect to embodiment two for treatment of lithium nickel cobaltaluminum oxide shown in FIG. 6, the flowsheet is described as follows:

In the leach reactor (180), spent lithium nickel cobalt aluminum oxidecathode materials for example with the chemical formulaLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or cobalt and/or aluminum that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,cobalt and aluminum are dissolved in solution producing a leach solutioncontaining nickel cobalt aluminum sulphate, nickel cobalt aluminumdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (188) wheresodium hydroxide is added and mixed to selectively precipitate nickel,cobalt and aluminum as nickel cobalt aluminum hydroxide and forming asolution containing mainly lithium sulphate, lithium dithionate, sodiumsulphate and sodium dithionate.

The precipitation reactions occur as follows:

(Ni,Co,Al)SO₄+2NaOH═(Ni,Co,Al)(OH)₂+Na₂SO₄ Near Complete Conversion

(Ni,Co,Al)S₂O₆+2NaOH═(Ni,Co,Al)(OH)₂+Na₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (182)to separate the nickel cobalt aluminum hydroxide which is rinsed toproduce a collected product (184).

The filtered solution is transferred to a second precipitation reactor(186) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (198)to separate the lithium carbonate which is rinsed to produce a collectedproduct (200).

The filtrate is transferred to a crystallizer (194) where part of thesodium sulphate and sodium dithionate is crystallized as solid crystalsby multi-effect crystallization or cooling crystallization. The solidsodium sulphate and sodium dithionate crystals are collected fromsolution with a centrifuge or filter (196). Heating of the sodiumsulphate and sodium dithionate crystals to approximately 120° C. (190)decomposes the sodium dithionate to sodium sulphate by-product and SO₂which can be recycled to the leach. The mother solution contains theremaining lithium sulphate, lithium dithionate, sodium sulphate, sodiumdithionate and water is recycled (192) back to the leach to minimizewater consumption and maximize lithium recovery of the overallflowsheet. Alternatively, a portion of the mother solution can betreated by nanofiltration (202) to produce clean water (204) for rinsingproducts and reuse of the spent rinse water (206, 208) back to theleach. The concentrate from nanofiltration (210) is recycled back to thecrystallizer to maximize sodium sulphate recovery. The lithium carbonate(200) and nickel cobalt aluminum hydroxide (184) collected products aremixed to the desired ratio of lithium, nickel, cobalt and aluminum andheat treated (212) to manufacture new cathode compounds for use inlithium ion batteries. If required, additional lithium, nickel, cobaltand or aluminum compounds may be added to the collected product toachieve the desired ratio of lithium, nickel, cobalt and aluminum priorto heat treatment.

With respect to embodiment three for treatment of lithium cobalt oxideshown in FIG. 7, the flowsheet is described as follows:

In the leach reactor (220), spent lithium ion battery cathode materialwith the chemical formula LiCoO₂ is combined and mixed with SO₂ andH₂SO₄ reagent and a solution containing water, and possibly lithiumand/or cobalt that has not been recovered previously from the laststages of the flowsheet. Lithium and cobalt are dissolved in solutionproducing a leach solution containing cobalt sulphate, cobaltdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (228) wherelithium hydroxide is added and mixed to selectively precipitate cobaltas cobalt hydroxide and forming a solution containing mainly lithiumsulphate and lithium dithionate.

The precipitation reactions occur as follows:

CoSO₄+2LiOH═Co(OH)₂+Li₂SO₄ Near Complete Conversion

CoS₂O₆+2LiOH═Co(OH)₂+Li₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (222)to separate the cobalt hydroxide which is rinsed to produce a collectedproduct (224).

The filtered solution is transferred to a second precipitation reactor(226) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (238)to separate the lithium carbonate which is rinsed (240). A portion ofthe lithium carbonate will be collected as a product (242). The otherportion of the lithium carbonate will be further mixed with calciumhydroxide (244) to produce a slurry containing dissolved lithiumhydroxide and solid calcium carbonate. The slurry will be filtered (246)to separate calcium carbonate solid and lithium hydroxide solution to bere-used to precipitate cobalt compounds (228).

The filtrate from the second filter (238) is transferred to acrystallizer (234) where part of the sodium sulphate and sodiumdithionate is crystallized as solid crystals by multi-effectcrystallization or cooling crystallization. The solid sodium sulphateand sodium dithionate crystals are collected from solution with acentrifuge or filter (236). Heating of the sodium sulphate and sodiumdithionate crystals to approximately 120° C. (230) decomposes the sodiumdithionate to sodium sulphate by-product and SO₂ which can be recycledto the leach. The mother solution contains the remaining lithiumsulphate, lithium dithionate, sodium sulphate, sodium dithionate andwater is recycled (232) back to the leach to minimize water consumptionand maximize lithium recovery of the overall flowsheet. Alternatively, aportion of the mother solution can be treated by nanofiltration (248) toproduce clean water (250) for rinsing products and reuse of the spentrinse water (252, 254) back to the leach. The concentrate fromnanofiltration (256) is recycled back to the crystallizer to maximizesodium sulphate recovery. The lithium carbonate (242) and cobalthydroxide (224) collected products are mixed to the desired ratio oflithium and cobalt and heat treated (258) to manufacture new cathodecompounds for use in lithium ion batteries. If required, additionallithium and or cobalt compounds may be added to the collected product toachieve the desired ratio of lithium and cobalt prior to heat treatment.

With respect to embodiment three for treatment of lithium nickelmanganese cobalt oxide shown in FIG. 8, the flowsheet is described asfollows:

In the leach reactor (270), spent lithium nickel manganese cobalt oxidecathode material for example with the chemical formulaLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or manganese and/or cobalt that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,manganese and cobalt are dissolved in solution producing a leachsolution containing nickel manganese cobalt sulphate, nickel manganesecobalt dithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (278) wherelithium hydroxide is added and mixed to selectively precipitate nickel,manganese and cobalt as nickel manganese cobalt hydroxide and forming asolution containing mainly lithium sulphate and lithium dithionate.

The precipitation reactions occur as follows:

(Ni,Mn,Co)SO₄+2LiOH═(Ni,Mn,Co)(OH)₂+Li₂SO₄ Near Complete Conversion

(Ni,Mn,Co)S₂O₆+2LiOH═(Ni,Mn,Co)(OH)₂+Li₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (272)to separate the nickel manganese cobalt hydroxide which is rinsed toproduce a collected product (274).

The filtered solution is transferred to a second precipitation reactor(276) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (288)to separate the lithium carbonate which is rinsed (290). A portion ofthe lithium carbonate will be collected as a product (292). The otherportion of the lithium carbonate will be further mixed with calciumhydroxide (294) to produce a slurry containing dissolved lithiumhydroxide and solid calcium carbonate. The slurry will be filtered (296)to separate calcium carbonate solid and lithium hydroxide solution to bere-used to precipitate cobalt compounds (278).

The filtrate from the second filter (288) is transferred to acrystallizer (284) where part of the sodium sulphate and sodiumdithionate is crystallized as solid crystals by multi-effectcrystallization or cooling crystallization. The solid sodium sulphateand sodium dithionate crystals are collected from solution with acentrifuge or filter (286). Heating of the sodium sulphate and sodiumdithionate crystals to approximately 120° C. (280) decomposes the sodiumdithionate to sodium sulphate by-product and SO₂ which can be recycledto the leach. The mother solution contains the remaining lithiumsulphate, lithium dithionate, sodium sulphate, sodium dithionate andwater is recycled (282) back to the leach to minimize water consumptionand maximize lithium recovery of the overall flowsheet. Alternatively, aportion of the mother solution can be treated by nanofiltration (298) toproduce clean water (300) for rinsing products and reuse of the spentrinse water (302, 304) back to the leach. The concentrate fromnanofiltration (306) is recycled back to the crystallizer to maximizesodium sulphate recovery. The lithium carbonate (292) and nickelmanganese cobalt hydroxide (274) collected products are mixed to thedesired ratio of lithium, nickel, manganese and cobalt and heat treated(308) to manufacture new cathode compounds for use in lithium ionbatteries. If required, additional lithium, nickel, manganese and orcobalt compounds may be added to the collected product to achieve thedesired ratio of lithium, nickel, manganese and cobalt prior to heattreatment.

With respect to embodiment three for treatment of lithium nickel cobaltaluminum oxide shown in FIG. 9, the flowsheet is described as follows:

In the leach reactor (320), spent lithium nickel cobalt aluminum oxidecathode material for example with the chemical formulaLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ is combined and mixed with SO₂ and H₂SO₄reagent and a solution containing water, and possibly lithium and/ornickel and/or cobalt and/or aluminum that has not been recoveredpreviously from the last stages of the flowsheet. Lithium, nickel,cobalt and aluminum are dissolved in solution producing a leach solutioncontaining nickel cobalt aluminum sulphate, nickel cobalt aluminumdithionate, lithium sulphate and lithium dithionate.

The leach solution is transferred to a precipitation reactor (328) wherelithium hydroxide is added and mixed to selectively precipitate nickel,cobalt and aluminum as nickel cobalt aluminum hydroxide and forming asolution containing mainly lithium sulphate and lithium dithionate.

The precipitation reactions occur as follows:

(Ni,Co,Al)SO₄+2LiOH═(Ni,Co,Al)(OH)₂+Li₂SO₄ Near Complete Conversion

(Ni,Co,Al)S₂O₆+2LiOH═(Ni,Co,Al)(OH)₂+Li₂S₂O₆ Near Complete Conversion

The slurry containing a mixture of solids and liquids is filtered (322)to separate the nickel cobalt aluminum hydroxide which is rinsed toproduce a collected product (324).

The filtered solution is transferred to a second precipitation reactor(326) where sodium carbonate is added and mixed to precipitate part ofthe dissolved lithium as lithium carbonate solid and forming a solutioncontaining mainly lithium sulphate, lithium dithionate, sodium sulphateand sodium dithionate.

The slurry containing a mixture of solids and liquids is filtered (338)to separate the lithium carbonate which is rinsed (340). A portion ofthe lithium carbonate will be collected as a product (342). The otherportion of the lithium carbonate will be further mixed with calciumhydroxide (344) to produce a slurry containing dissolved lithiumhydroxide and solid calcium carbonate. The slurry will be filtered (346)to separate calcium carbonate solid and lithium hydroxide solution to bere-used to precipitate nickel, cobalt and aluminum compounds (328).

The filtrate from the second filter (338) is transferred to acrystallizer (334) where part of the sodium sulphate and sodiumdithionate is crystallized as solid crystals by multi-effectcrystallization or cooling crystallization. The solid sodium sulphateand sodium dithionate crystals are collected from solution with acentrifuge or filter (336). Heating of the sodium sulphate and sodiumdithionate crystals to approximately 120° C. (330) decomposes the sodiumdithionate to sodium sulphate by-product and SO₂ which can be recycledto the leach. The mother solution contains the remaining lithiumsulphate, lithium dithionate, sodium sulphate, sodium dithionate andwater is recycled (332) back to the leach to minimize water consumptionand maximize lithium recovery of the overall flowsheet. Alternatively, aportion of the mother solution can be treated by nanofiltration (348) toproduce clean water (350) for rinsing products and reuse of the spentrinse water (352, 354) back to the leach. The concentrate fromnanofiltration (356) is recycled back to the crystallizer to maximizesodium sulphate recovery. The lithium carbonate (342) and nickel cobaltaluminum hydroxide (324) collected products are mixed to the desiredratio of lithium, nickel, cobalt and aluminum and heat treated (358) tomanufacture new cathode compounds for use in lithium ion batteries. Ifrequired, additional lithium, nickel, cobalt and or aluminum compoundsmay be added to the collected product to achieve the desired ratio oflithium, nickel, cobalt and aluminum prior to heat treatment.

Examples illustrating the invention:

1. Lithium Cobalt Oxide Leached with Sulphur Dioxide and Sulphuric Acid(Test #LT4)

Lithium cobalt oxide consisting of the chemical formula LiCoO₂ (AlfaAesar) was used for this test work. Leaching was conducted by mixing 25grams of LiCoO₂ with 250 mL of 2 molar sulphuric acid. Sulphur dioxidegas was continuously sparged into the leach solution to maintain anoxidation-reduction potential (ORP) of ≤400 mV. The leach vesselconsisted of a three-port round bottom flask, and stirring was conductedwith a magnetic stir bar. One port of the flask was used to monitor ORP,a condenser was added to another port to condense vapours back into thevessel and the other port was used to measure temperature. Theexperiment was conducted without temperature control. The leaching wasdetermined to be exothermic as the temperature rose to as high as 71° C.after 5 minutes of leaching and further cooling down to 21 C after 120minutes of experimentation. Inductively coupled plasma spectroscopy(ICP) analysis of the solutions showed that 100% of the lithium andcobalt were extracted after 5 minutes of leaching.

2. Lithium Cobalt Oxide Leached with Metabisulphite and Sulphuric Acid(Test #LT6)

Leaching was conducted by mixing 12.5 grams of LiCoO₂ with 250 mL of 2molar sulphuric acid and 0.67 molar sodium metabisulphite. The leachvessel consisted of a three-port round bottom flask, and stirring wasconducted with a magnetic stir bar. One port of the flask was used tomonitor ORP, a condenser was added to another port to condense vapoursback into the vessel and the other port was used to measure temperature.The experiment was conducted without temperature control. The leachingwas determined to be exothermic as the temperature rose to as high as60° C. after 5 minutes of leaching and further cooling down to 25° C.after 120 minutes of experimentation. ICP analysis of the solutionsshowed that 100% of the lithium and cobalt were extracted after 5minutes of leaching.

3. Precipitation of Cobalt and Lithium as Cobaltous Carbonate andLithium Carbonate (Test #PTCL1)

A 200 mL solution containing 5.59 g/L lithium and 50.01 g/L cobalt, atpH 1.59, was prepared by leaching lithium cobalt oxide with sulphurdioxide in combination with sulphuric acid. A precipitation test wasconducted by adding 31.83 grams of anhydrous sodium carbonate (which iscalculated to be 1.2 times the stoichiometric amount of sodium carbonaterequired to precipitate all of the lithium and cobalt as carbonate).Afterwards, 10 molar sodium hydroxide was added to raise the pH to11.14. The test was conducted in a 1000 mL beaker with an overheadstirrer. The slurry was filtered; 35.33 grams of residue and 118 mL offiltrate were collected. Evaporation was noticed. The residue was washedwith saturated lithium carbonate solution, re-filtered and dried.Analysis of the residue indicated that 100% of the cobalt and 82.11% ofthe lithium was precipitated as a mixed cobalt and lithium carbonate.

4. Precipitation of Cobalt as Cobaltous Hydroxide (Test #PTC3-2)

A 450 mL solution containing 5.59 g/L lithium and 50.01 g/L cobalt, atpH 1.59, was prepared by leaching lithium cobalt oxide with sulphurdioxide in combination with sulphuric acid. A precipitation test wasconducted by slowly adding 10 molar sodium hydroxide to raise the pH to10.61 to precipitate cobalt. The test was conducted in a 1000 mL beakerwith an overhead stirrer. The slurry was filtered; 46.48 grams ofresidue and 390 mL of filtrate was collected. The residue was washedwith deionized water, re-filtered and dried. Analysis of the residueindicated that 100% of the cobalt was selectively precipitated as cobalthydroxide from the solution containing lithium and cobalt. The finalresidue contained a trace amount of lithium (approximately 0.0292%)which could likely be further purified by additional rinsing.

5. Precipitation of Lithium as Lithium Carbonate (Test #PTL 3-2)

A 385 mL solution remaining from the filtrate after Test #PTC3-2 abovewas used for this test. A precipitation test was conducted by adding 25grams of sodium carbonate monohydrate (calculated to be 1.2 times thestoichiometric amount required to precipitate all of the lithium aslithium carbonate to the solution). The test was conducted in a 1000 mLbeaker with an overhead mixer. The slurry was filtered; 7.82 grams ofresidue and 318 mL of filtrate were collected. The residue was washedwith saturated lithium carbonate solution, re-filtered and dried.Analysis of the residue indicates that 53.9% of the lithium wasprecipitated as lithium carbonate.

6. Dithionate Generation from Leaching Lithium Cobalt Oxide Leached withSulphur Dioxide and Sulphuric Acid

Lithium cobalt oxide consisting of the chemical formula LiCoO₂ (AlfaAesar) was used for this test work. A number of leach experiments wereconducted by mixing a range of 36 to 50 grams of LiCoO₂ with 250 mL ofsulphuric acid ranging from 0.8 molar to 1.5 molar concentration.Sulphur dioxide gas was continuously sparged into the leach solution.The range of final oxidation-reduction potential (ORP) tested wasbetween 102 mV to 401 mV. The leach vessel consisted of a three-portround bottom flask, and stirring was conducted with a magnetic stir bar.One port of the flask was used to monitor ORP, a condenser was added toanother port to condense vapours back into the vessel and the other portwas used to measure temperature. The experiment was conducted withouttemperature control. After leaching for 120 minutes samples removed foranalysis of dithionate by ion chromatography. The results are summarizedin Table 1.

TABLE 1 Test Number S₂O₆ ²⁻ (mg/L) LT 18 27150 LT 19 30294 LT 20 15207LT 21 23069 LT 22 13290 LT 23 30953 LT 24 19951 LT 25 9260 LT 26 10386

7. Locked Cycling Testing for Treating Lithium Cobalt Oxide

Lithium cobalt oxide consisting of the chemical formula LiCoO₂ (AlfaAesar) was used for this test work. Lithium cobalt oxide was processedin a locked cycle manner to simulate the major unit operations in theflowsheet described in embodiment two. The locked cycle testingdemonstrates the removal of sulphate and dithionate from the circuitwhich enables un-recovered lithium and water at the end of the flowsheetfrom the previous cycle to be recirculated to the front end of theflowsheet of the subsequent cycle to be recovered.

The leaching condition consists of pH control to approximately 1.5; 1.2MH₂SO₄ in the leaching head; 8% pulp density; and SO₂ sparing with atarget ORP of 350 mV. For each leaching stage within 4 cycles, all thehead solids visually disappeared after 2 hours of SO₂ reductiveleaching.

Leachate from previous leaching stage is adjusted to pH 11 by 10M NaOHto precipitate the dissolved cobalt as Co(OH)₂. 2 re-pulp wash steps andfiltration was then followed. The wet solids were dried at 60° C.

Filtrate from the previous step was then mixed with 1.2 timesstoichiometric Na₂CO₃ with respect to lithium concentration measured byICP. The mixed solution was then heated to 95° C. for 30 minutes beforefiltering out the Li₂CO₃ precipitate. The precipitate was washed withsaturated Li₂CO₃ at 95° C. Except for Lock Cycle #1, all saturatedLi₂CO₃ wash solutions were prepared by Li₂CO₃ solids generated fromprevious cycle. In the locked cycle, lithium is expected to accumulatein solution result in increasing Li recovery. Results from ICP andcalculation confirmed this conclusion. Calculated lithium recovery foreach cycle of the flowsheet is shown in Table 2.

TABLE 2 Lock Cycle No. % Lithium Recovery 1 32% 2 36% 3 68% 4 76%Filtrate from the previous step containing a mixture of sodium sulphate,sodium dithionate and un-recovered lithium ion solution is cooled to 5°C. to for 2 hours with gentle mixing with an overhead mixer tocrystallize sodium sulphate decahydrate and sodium dithionate dihydrate.The crystals were collected by filtration and dried as 60° C. to collectanhydrous crystals. The weight of the dry crystals for Cycles 1 to 4 isshown in Table 3.

TABLE 3 Weight of Dry Lock Cycle No. Crystals (g) 1 26.16 2 59.77 378.50 4 74.25An Example of a nanofiltration step is described in Example 20.8. Lithium Nickel Manganese Cobalt Oxide Leached with Sulphur Dioxideand Sulphuric Acid (Test #NMC3-5)

Lithium nickel manganese cobalt oxide consisting of the chemical formulaLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ (Sigma Aldrich) was used for this testwork. Leaching was conducted by mixing 30 grams ofLiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ with 255 mL of 1.2 molar sulphuric acid.Sulphur dioxide gas was continuously sparged into the leach solution tomaintain an oxidation-reduction potential (ORP) of =550 mV. The leachvessel consisted of a three-port round bottom flask, and stirring wasconducted with a magnetic stir bar. One port of the flask was used tomonitor ORP, a condenser was added to another port to condense vapoursback into the vessel and the other port was used to measure temperature.The experiment was conducted without temperature control. The leachingwas determined to be exothermic as the temperature rose to as high as66° C. after 30 minutes of leaching and further cooling down to 28 Cafter 120 minutes of experimentation. Inductively coupled plasmaspectroscopy (ICP) analysis of the solutions showed that 100% of thelithium, nickel, manganese and cobalt were extracted after 120 minutesof leaching. Ion Chromatography analysis showed that the final leachsolution contained 24.1 g/L dithionate.

9. Precipitation of Nickel, Manganese and Cobalt as (Ni,Mn,Co)(OH)₂ withNaOH (Test #NMC-2-PTC 11)

A 200 mL solution containing 7.71 g/L lithium, 19.83 g/L nickel, 18.09g/L manganese and 19.38 g/L cobalt, at pH 0.8, was prepared by leachinglithium nickel manganese cobalt oxide with sulphur dioxide incombination with sulphuric acid. A precipitation test was conducted byslowly adding 10 molar sodium hydroxide to raise the pH to 10.70 toprecipitate nickel, manganese and cobalt. The test was conducted in a500 mL beaker with a magnetic stirrer. The slurry was filtered. 18.70grams of dry residue and 140 mL of filtrate was collected. The residuewas washed with deionized water, re-filtered and dried. Analysis of theresidue indicated that 100% nickel, 100% manganese and 100% of thecobalt were precipitated as metal hydroxide from the solution containinglithium, nickel, manganese and cobalt. The final residue contained asmall amount of lithium (approximately 0.155%) which could likely befurther purified by additional rinsing.

10. Precipitation of Lithium as Lithium Carbonate Following HydroxidePrecipitation of Nickel, Manganese and Cobalt with NaOH (Test #NMC-2-PTL11)

The remnants from the filtrate after Test #NMC-2-PTC-11 were used forthis test. A precipitation test was conducted by adding 14.12 grams ofsodium carbonate (calculated to be 1.2 times the stoichiometric amountrequired to precipitate all of the lithium as lithium carbonate to thesolution). The test was conducted in a 500 mL beaker with a magneticstirrer at 95° C. for 15 minutes. The slurry was filtered; 2.39 grams ofdry residue and 130 mL of filtrate were collected. The residue waswashed with saturated lithium carbonate solution, re-filtered and dried.Analysis of the residue indicates that 34.6% of the lithium wasprecipitated as lithium carbonate.

11. Precipitation of Nickel, Manganese and Cobalt as (Ni,Mn,Co)(OH)₂with LiOH (Test #NMC-2-CT-PTC 3)

A 200 mL solution containing 7.30 g/L lithium, 18.27 g/L nickel, 17.05g/L manganese and 18.24 g/L cobalt, at pH 0.66, was prepared by leachinglithium nickel manganese cobalt oxide with sulphur dioxide incombination with sulphuric acid. A precipitation test was conducted byslowly adding 3.34 molar lithium hydroxide to raise the pH to 11.07 toprecipitate nickel, manganese and cobalt. The test was conducted in a500 mL beaker with a magnetic stirrer. The slurry was filtered; 18.24grams of residue and 206 mL of filtrate was collected. The residue waswashed with deionized water, re-filtered and dried. Analysis of theresidue indicated that 100% nickel, 100% manganese and 100% of thecobalt were precipitated as metal hydroxide from the solution containinglithium, nickel, manganese and cobalt. The final residue contained asmall amount of lithium (approximately 0.787%) which could likely befurther purified by additional rinsing.

12. Precipitation of Lithium as Lithium Carbonate Following HydroxidePrecipitation of Nickel, Manganese and Cobalt with LiOH (Test#NMC-2-CT-PTL 3)

The remnants from the filtrate after Test #NMC-2-CT-PTC3 were used forthis test. A precipitation test was conducted by adding 27.74 grams ofsodium carbonate (calculated to be 1.2 times the stoichiometric amountrequired to precipitate all of the lithium as carbonate to thesolution). The test was conducted in a 500 mL beaker with a magneticstirrer at 95° C. for 15 minutes. The slurry was filtered; 12.12 gramsof dry residue and 184 mL of filtrate were collected. The residue waswashed with saturated lithium carbonate solution, re-filtered and dried.Analysis of the residue indicates that 49.8% of the lithium wasprecipitated as lithium carbonate.

13. Locked Cycling Testing for Treating Lithium Nickel Manganese CobaltOxide Lithium Nickel Manganese Cobalt Oxide Consisting of the ChemicalFormula

LiNi_(0.33)Mn_(0.33)Co_(0.33)O₂ (Sigma Aldrich) was used for this testwork. Lithium nickel manganese cobalt oxide was processed in a lockedcycle manner to simulate the major unit operations in the flowsheetdescribed in embodiment three. The locked cycle testing demonstrates theremoval of sulphate and dithionate from the circuit which enablesun-recovered lithium and water at the end of the flowsheet from theprevious cycle to be recirculated to the front end of the flowsheet ofthe subsequent cycle to be recovered.

The leaching condition consists treating 100 g of sample with pH controlto approximately 1.5; 1.5M H₂SO₄ in the leaching head; 10% pulp density;and SO₂ sparing with a target ORP of 550 mV. For each leaching stagewithin 4 cycles, the head solids visually disappeared after 2 hours ofSO₂ reductive leaching.

Leachate from previous leaching stage is adjusted to pH 11 by saturatedLiOH to precipitate the dissolved nickel, manganese and cobalt as(Ni,Mn,Co)(OH)₂. Two re-pulp wash steps and filtration then followed.The wet solids were dried at 60° C.

Filtrate from the previous step was then mixed with 1.0 timesstoichiometric Na₂CO₃ with respect to lithium concentration measured byICP. The mixed solution was then headed to 95° C. for 30 minutes beforefiltering out the Li₂CO₃ precipitate. The precipitate was washed withsaturated Li₂CO₃ at 95° C. Except for Lock Cycle #1, all saturatedLi₂CO₃ wash solutions were prepared by Li₂CO₃ solids generated fromprevious cycle. In the locked cycle, lithium is expected to accumulatein solution result in increasing Li recovery. Results from ICP andcalculation confirmed this conclusion. Calculated lithium recovery foreach cycle of the flowsheet are shown in Table 4.

TABLE 4 Lock Cycle No. % Lithium Recovery 1 47% 2 67% 3 78% 4 100%Filtrate from the previous step containing a mixture of sodium sulphate,sodium dithionate and un-recovered lithium ion solution was cooled to 5°C. to for 2 hours with gentle mixing using an overhead mixer tocrystallize sodium sulphate decahydrate and sodium dithionate dihydrate.The crystals were collected by filtration and dried as 60° C. to collectanhydrous crystals. The weights of the dry crystals for Cycles 1 to 4are shown in Table 5.

TABLE 5 Weight of Dry Lock Cycle No. Crystals (g) 1 53.22 2 108.29 371.75 4 236.11An Example of a nanofiltration step is described in Example 20.14. Lithium Nickel Cobalt Aluminum Oxide Leached with Sulphur Dioxideand Sulphuric Acid (Test #NCA-LT8)

Lithium nickel cobalt aluminum oxide consisting of the chemical formulaLiNi_(0.08)Co_(0.5)Al_(0.05)O₂ (MTI Corp) was used for this test work.Leaching was conducted by mixing 30 grams ofLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ with 245 mL of 1.2 molar sulphuric acid.Sulphur dioxide gas was continuously sparged into the leach solution tomaintain an oxidation-reduction potential (ORP) of =550 mV. The leachvessel consisted of a four-port glass reactor, and stirring wasconducted with an overhead mixer. One port of the flask was used tomonitor ORP, a condenser was added to another port to condense vapoursback into the vessel, the other port was used to measure temperature andthe final port for the overhead mixer. The experiment was conductedwithout temperature control. The leaching was determined to beexothermic as the temperature rose to as high as 88° C. after 30 minutesof leaching and further cooling down to 50° C. after 120 minutes ofexperimentation. Inductively coupled plasma spectroscopy (ICP) analysisof the solutions showed that 100% of the lithium, nickel, cobalt andaluminum were extracted after 120 minutes of leaching. IonChromatography analysis showed that the final leach solution contained11.3 g/L dithionate.

15. Precipitation of Nickel, Cobalt and Aluminum as (Ni,Co,Al)(OH)₂ withNaOH (Test #NCA-PTC 1)

A 200 mL solution containing 8.63 g/L lithium, 57.82 g/L nickel, 10.54g/L cobalt and 1.17 g/L aluminum, at pH 1.06, was prepared by leachinglithium nickel cobalt aluminum oxide with sulphur dioxide in combinationwith sulphuric acid. A precipitation test was conducted by slowly adding10 molar sodium hydroxide to raise the pH to 11.09 to precipitatenickel, cobalt and aluminum. The test was conducted in a 500 mL beakerwith a magnetic stirrer. The slurry was filtered. 27.15 grams of dryresidue and 135 mL of filtrate was collected. The residue was washedwith deionized water, re-filtered and dried. Analysis of the residueindicated that 100% nickel, 100% manganese and 100% of the cobalt wereprecipitated as metal hydroxide from the solution containing lithium,nickel, manganese and cobalt. The final residue contained a small amountof lithium (approximately 0.078%) which could likely be further purifiedby additional rinsing.

16. Precipitation of Lithium as Lithium Carbonate Following HydroxidePrecipitation of Nickel, Cobalt and Aluminum with NaOH (Test #NCA-PTL 1)

The remnants from the filtrate after Test #NCA-PTL 1 were used for thistest. A precipitation test was conducted by adding 15.82 grams of sodiumcarbonate (calculated to be 1.2 times the stoichiometric amount requiredto precipitate all of the lithium as carbonate to the solution). Thetest was conducted in a 500 mL beaker with a magnetic stirrer at 95° C.for 15 minutes. The slurry was filtered; 2.88 grams of dry residue and125 mL of filtrate were collected. The residue was washed with saturatedlithium carbonate solution, re-filtered and dried. Analysis of theresidue indicated that 31.5% of the lithium was precipitated as lithiumcarbonate.

17. Precipitation of Nickel, Cobalt and Aluminum as (Ni,Co,Al)(OH)₂ withLiOH (Test #NCA-CT-PTC 2)

A 200 mL solution containing 6.64 g/L lithium, 46.84 g/L nickel, 8.45g/L cobalt and 0.89 g/L aluminum, at pH 0.35, was prepared by leachinglithium nickel cobalt aluminum oxide with sulphur dioxide in combinationwith sulphuric acid. A precipitation test was conducted by slowly adding4.44 molar lithium hydroxide to raise the pH to 11.03 to precipitatenickel, cobalt and aluminum. The test was conducted in a 500 mL beakerwith a magnetic stirrer. The slurry was filtered; 18.55 grams of residueand 202 mL of filtrate was collected. The residue was washed withdeionized water, re-filtered and dried. Analysis of the residueindicated that 100% nickel, 100% cobalt and 100% of the aluminum wereprecipitated as metal hydroxide from the solution containing lithium,nickel, cobalt and aluminum. The final residue contained a small amountof lithium (approximately 0.648%) which could likely be further purifiedby additional rinsing.

18. Precipitation of Lithium as Lithium Carbonate Following HydroxidePrecipitation of Nickel, Cobalt and Aluminum with LiOH (Test #NCA-CT-PTL2)

The remnants from the filtrate after Test #NCA-CT-PTC 2 were used forthis test. A precipitation test was conducted by adding 27.31 grams ofsodium carbonate (calculated to be 1.0 times the stoichiometric amountrequired to precipitate all of the lithium as carbonate to thesolution). The test was conducted in a 500 mL beaker with a magneticstirrer at 95° C. for 15 minutes. The slurry was filtered; 14.04 gramsof dry residue and 185 mL of filtrate was collected. The residue waswashed with saturated lithium carbonate solution, re-filtered and dried.Analysis of the residue indicates that 55.97% of the lithium wasprecipitated as lithium carbonate.

19. Locked Cycling Testing for Treating Lithium Nickel Cobalt AluminumOxide

Lithium nickel cobalt aluminum oxide consisting of the chemical formulaLiNi_(0.8)Co_(0.15)Al_(0.05)O₂ (MTI Corp) was used for this test work.Lithium nickel cobalt aluminum oxide was processed in a locked cyclemanner to simulate the major unit operations in the flowsheet describedin embodiment three. The locked cycle testing demonstrates the removalof sulphate and dithionate from the circuit which enables un-recoveredlithium and water at the end of the flowsheet from the previous cycle tobe recirculated to the front end of the flowsheet of the subsequentcycle to be recovered.

Leaching consisted of treating 400 g of sample with pH control toapproximately 1.5; 1.2M H₂SO₄ in the leaching head; 10% pulp density;and SO₂ sparing with a target ORP of 550 mV. For each leaching stagewithin 7 cycles, the head solids visually disappeared after 2 hours ofSO₂ reductive leaching.

Leachate from previous leaching stage was adjusted to pH 10.5 bysaturated LiOH to precipitate the dissolved nickel, cobalt and aluminumas (Ni,Co,Al)(OH)₂. Two re-pulp wash steps and filtration then followed.The wet solids were dried at 60° C.

Filtrate from the previous step was then mixed with 1.2 timesstoichiometric Na₂CO₃ with respect to lithium concentration measured byICP. The mixed solution was then heated to 95° C. for 30 minutes beforefiltering out the Li₂CO₃ precipitate. The precipitate was washed withsaturated Li₂CO₃ at 95° C. With the exception of Lock Cycle #1, allsaturated Li₂CO₃ wash solutions were prepared by Li₂CO₃ solids generatedfrom previous cycle. In the locked cycle, Lithium was expected toaccumulate in solution result in increased Li recovery. Results from ICPand calculation confirmed this conclusion. Calculated lithium recoveryfor each cycle of the flowsheet are shown in Table 6.

TABLE 6 Lock Cycle No. % Lithium Recovery 1 51% 2 62% 3 69% 4 70% 5 80%6 86% 7 100%

Filtrate from the previous step containing a mixture of sodium sulphate,sodium dithionate and un-recovered lithium ion solution was cooled to 5°C. to for 2 hours with gentle mixing with an overhead mixer tocrystallize sodium sulphate decahydrate and sodium dithionate dihydrate.The crystals were collected by filtration and dried as 60° C. to collectanhydrous crystals. The weights of the dry crystals for Cycles 1 to 4are shown in Table 7.

TABLE 7 Weight of Dry Lock Cycle No. Crystals (g) 1 67.9 2 185.3 3 161.44 175.0 5 218.7 6 109.3 7 205.6An Example of a nanofiltration step is described in Example 20.

20. Nanofiltration

A nanofiltration test was conducted by pumping a feed solutioncontaining 32.23 g/L sulphate and 24.0 dithionate through a Dow FilmtecNF270-400 nanofiltration membrane. The feed flow rate was set at 5.65L/min. The pressure at the inlet of the membrane was measured at 29.1Bar. The pressure at the concentrate outlet was measured at 28.5 Bar.The permeate flowrate through the membrane was measured at 0.65 L/min. Asample of the permeate was collected and sulphate was measured as 2.30g/L and dithionate as 2.84 g/L by ion chromatography. The concentrateflow rate was calculated as 5.0 L/min. The concentrate was calculated tocontain 36.13 g/L sulphate and 26.80 g/L dithionate. The sulphaterejection was calculated to be 92.2% and the dithionate rejection wascalculated to be 85.5%.

Although a preferred embodiment of the invention has been disclosed forpurposes of illustration, it should be understood that various changes,modifications and substitutions may be incorporated in the embodimentwithout departing from the spirit of the invention, which is defined bythe claims which follow.

What is claimed is:
 1. A process of water removal and/or recycling fromsodium sulphate and/or sodium dithionate containing liquors derived fromprocessing cobalt resource material essentially free of lithium,comprising the steps of: a. precipitation of cobalt as cobaltouscarbonate in whole or in part followed by its removal in whole or inpart from the liquor by centrifugation or filtration; b. crystallizationof sodium sulphate and sodium dithionate to separate the majority ofsodium sulphate and sodium dithionate from solution; c. removal ofsodium sulphate and sodium dithionate crystals; heating of sodiumsulphate and sodium dithionate crystals to form anhydrous sodiumsulphate, sulphur dioxide and water (steam); and e. separation ofanhydrous sodium sulphate.
 2. A process of water removal and/orrecycling from sodium sulphate and/or sodium dithionate containingliquors derived from processing cobalt resource material containinglithium, comprising the steps of: a. precipitation of cobalt ascobaltous carbonate in whole or in part and lithium in whole or in partas lithium carbonate followed by their removal in whole or in part fromthe liquor for example by centrifugation or filtration; b.crystallization of sodium sulphate and sodium dithionate to separate themajority of sodium sulphate and sodium dithionate from solution; c.removal of sodium sulphate and sodium dithionate crystals; and d.separation of anhydrous sodium sulphate.
 3. A process of water removaland/or recycling from sodium sulphate and/or sodium dithionatecontaining liquors derived from processing cobalt resource materialessentially free of lithium, comprising the steps of: a. precipitationof cobalt as cobaltous hydroxide in whole or in part followed itsremoval in whole or in part from the liquor by centrifugation orfiltration; b. crystallization of sodium sulphate and sodium dithionateto separate the majority of sodium sulphate and sodium dithionate fromsolution; c. removal of sodium sulphate and sodium dithionate crystals;heating of sodium sulphate and sodium dithionate crystals to formanhydrous sodium d. sulphate, sulphur dioxide and water (steam); and e.separation of anhydrous sodium sulphate.
 4. A process of water removaland/or recycling from sodium sulphate and/or sodium dithionatecontaining liquors derived from processing cobalt resource materialcontaining lithium, comprising the steps of: a. precipitation of cobaltas cobaltous hydroxide in whole or in part followed by its removal inwhole or in part from the liquor by centrifugation or filtration;precipitation of lithium as lithium carbonate in whole or in part fromthe cobaltous hydroxide stripped liquor of 4a, followed by its removalin whole or in part from the liquor for example by centrifugation; b.crystallization of sodium sulphate and sodium dithionate to separate themajority of sodium sulphate and sodium dithionate from solution; c.removal of sodium sulphate and sodium dithionate crystals; and d.separation of anhydrous sodium sulphate.
 5. The process of claim 1 inwhich carbonate is sodium carbonate.
 6. The process of claim 2 in whichcarbonate is sodium carbonate.
 7. The process of claim 3 in whichhydroxide is sodium hydroxide.
 8. The process of claim 4 in whichhydroxide is sodium hydroxide.
 9. The process of claim 5 in which sodiumcarbonate is in aqueous solution.
 10. The process of claim 7 in whichsodium hydroxide is in aqueous solution.
 11. The process of claim 1,wherein sulphate and dithionate are derived from sulphur dioxide,sulphurous acid, metabisulphite, bisulphate with or without sulphuricacid.
 12. The process of claim 2, wherein sulphate and dithionate arederived from sulphur dioxide, sulphurous acid, metabisulphite,bisulphate with or without sulphuric acid.
 13. The process of claim 3,wherein sulphate and dithionate are derived from sulphur dioxide,sulphurous acid, metabisulphite, bisulphate with or without sulphuricacid.
 14. The process of claim 4, wherein sulphate and dithionate arederived from sulphur dioxide, sulphurous acid, metabisulphite,bisulphate with or without sulphuric acid.
 15. The process of claim 1,wherein nanofiltration of crystallizer liquor separates water fromdithionate and sulfate.
 16. The process of claim 2, whereinnanofiltration of crystallizer liquor separates water from dithionateand sulfate.
 17. The process of claim 3, wherein nanofiltration ofcrystallizer liquor separates water from dithionate and sulfate.
 18. Theprocess of claim 4, wherein nanofiltration of crystallizer liquorseparates water from dithionate and sulfate.
 19. The process of claim 1,including the step of recycling of concentrated sodium dithionate andsodium sulphate.
 20. The process of claim 2, including the step ofrecycling of concentrated sodium dithionate and sodium sulphate.
 21. Theprocess of claim 3, including the step of recycling of concentratedsodium dithionate and sodium sulphate.
 22. The process of claim 4,including the step of recycling of concentrated sodium dithionate andsodium sulphate.
 23. The process of claim 2, wherein lithium is lithiumions.
 24. The process of claim 4, wherein lithium is lithium ions. 25.The process of claim 1, including the presence of manganese in theprocess.
 26. The process of claim 2, including the presence of manganesein the process.
 27. The process of claim 3, including the presence ofmanganese in the process.
 28. The process of claim 4, including thepresence of manganese in the process.
 29. The process of claim 25, inwhich manganese is recovered as manganese carbonate or manganesehydroxide.
 30. The process of claim 26, in which manganese is recoveredas manganese carbonate or manganese hydroxide.
 31. The process of claim27, in which manganese is recovered as manganese carbonate or manganesehydroxide.
 32. The process of claim 28, in which manganese is recoveredas manganese carbonate or manganese hydroxide.
 33. The process of claim1, including the presence of nickel in the process.
 34. The process ofclaim 2, including the presence of nickel in the process.
 35. Theprocess of claim 3, including the presence of nickel in the process. 36.The process of claim 4, including the presence of nickel in the process.37. The process of claim 33, wherein nickel is recovered as nickelcarbonate or nickel hydroxide.
 38. The process of claim 34, whereinnickel is recovered as nickel carbonate or nickel hydroxide.
 39. Theprocess of claim 35, wherein nickel is recovered as nickel carbonate ornickel hydroxide.
 40. The process of claim 36, wherein nickel isrecovered as nickel carbonate or nickel hydroxide.
 41. The process ofclaim 1, including the presence of aluminum in the process.
 42. Theprocess of claim 2, including the presence of aluminum in the process.43. The process of claim 3, including the presence of aluminum in theprocess.
 44. The process of claim 4, including the presence of aluminumin the process.
 45. The process of claim 41, wherein aluminum isrecovered as aluminum carbonate or aluminum hydroxide.
 46. The processof claim 42, wherein aluminum is recovered as aluminum carbonate oraluminum hydroxide.
 47. The process of claim 43, wherein aluminum isrecovered as aluminum carbonate or aluminum hydroxide.
 48. The processof claim 44, wherein aluminum is recovered as aluminum carbonate oraluminum hydroxide.
 49. The process of claim 1, in which theprecipitated cobaltous carbonate is used to manufacture cathodematerials for lithium ion batteries.
 50. The process of claim 2, inwhich the precipitated cobaltous carbonate is used to manufacturecathode materials for lithium ion batteries.
 51. The process of claim 3,in which the precipitated cobaltous carbonate is used to manufacturecathode materials for lithium ion batteries.
 52. The process of claim 4,in which the precipitated cobaltous carbonate is used to manufacturecathode materials for lithium ion batteries.
 53. The process of claim 2,in which the precipitated lithium carbonate is used to manufacturecathode materials from lithium ion batteries.
 54. The process of claim 4in which the precipitated lithium carbonate is used to manufacturecathode materials from lithium ion batteries.
 55. The process of claim29 in which the manganese carbonate or manganese hydroxide is used tomanufacture cathode materials for lithium ion batteries.
 56. The processof claim 30 in which the manganese carbonate or manganese hydroxide isused to manufacture cathode materials for lithium ion batteries.
 57. Theprocess of claim 31 in which the manganese carbonate or manganesehydroxide is used to manufacture cathode materials for lithium ionbatteries.
 58. The process of claim 32 in which the manganese carbonateor manganese hydroxide is used to manufacture cathode materials forlithium ion batteries.
 59. The process of claim 37 in which nickelcarbonate or nickel hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 60. The process of claim 38 in which nickelcarbonate or nickel hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 61. The process of claim 39 in which nickelcarbonate or nickel hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 62. The process of claim 40 in which nickelcarbonate or nickel hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 63. The process of claim 45 in which aluminumcarbonate or aluminum hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 64. The process of claim 46 in which aluminumcarbonate or aluminum hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 65. The process of claim 47 in which aluminumcarbonate or aluminum hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 66. The process of claim 48 in which aluminumcarbonate or aluminum hydroxide is used to manufacture cathode materialsfor lithium ion batteries.
 67. The process of claim 2 wherein the cobaltresource material contains lithium ion battery cathode material.
 68. Theprocess of claim 4 wherein the cobalt resource material contains lithiumion battery cathode material.
 69. The process of claim 1 wherein thecobalt resource material is cobalt containing ore.
 70. The process ofclaim 3, wherein the cobalt resource material is cobalt containing ore.